Hi, I find this message (Under the whole log is pasted) in the logs, is it a bug? what does snapd have to do with the Btrfs fiel system?
journalctl | grep btrfs
feb 01 17:32:26 emanuc sudo[11137]: emanu : TTY=pts/2 ; PWD=/home/emanu ; USER=root ; COMMAND=/usr/bin/apt install btrfsmaintenance
feb 01 17:43:58 emanuc snapd[12908]: udevmon.go:190: udev monitor observed remove event for unknown device “/sys/kernel/slab/btrfs_inode/cgroup/btrfs_inode(851:packagekit.service)”
feb 01 17:46:19 emanuc 05efi[30410]: debug: /dev/sdb1 is btrfs partition: exiting
feb 01 17:46:19 emanuc 05efi[30460]: debug: /dev/sdc1 is btrfs partition: exiting
feb 01 23:25:39 emanuc 05efi[23024]: debug: /dev/sdb1 is btrfs partition: exiting
feb 01 23:26:05 emanuc 05efi[23827]: debug: /dev/sdb1 is btrfs partition: exiting
feb 01 23:26:37 emanuc 05efi[953]: debug: /dev/sdb1 is btrfs partition: exiting
feb 01 23:30:57 emanuc snapd[1350]: udevmon.go:190: udev monitor observed remove event for unknown device "/sys/kernel/slab/btrfs_inode/cgroup/btrfs_inode(383:systemd-fsckd.service)"
feb 02 12:33:55 emanuc snapd[1359]: udevmon.go:190: udev monitor observed remove event for unknown device "/sys/kernel/slab/btrfs_inode/cgroup/btrfs_inode(375:systemd-fsckd.service)"
feb 02 13:59:06 emanuc snapd[1326]: udevmon.go:190: udev monitor observed remove event for unknown device "/sys/kernel/slab/btrfs_inode/cgroup/btrfs_inode(389:systemd-fsckd.service)"
feb 02 14:14:37 emanuc timeshift-gtk.desktop[2705]: Cartella creata: /mnt/timeshift/backup/timeshift-btrfs/snapshots/2019-02-02_14-14-37
feb 02 14:14:38 emanuc timeshift-gtk.desktop[2705]: Sottovolume di snapshot creato: /mnt/timeshift/backup/timeshift-btrfs/snapshots/2019-02-02_14-14-37/@
feb 02 14:14:38 emanuc timeshift-gtk.desktop[2705]: Creato file di controllo: /mnt/timeshift/backup/timeshift-btrfs/snapshots/2019-02-02_14-14-37/info.json
feb 02 14:14:46 emanuc timeshift-gtk.desktop[2705]: Cartella eliminata: /mnt/timeshift/backup/timeshift-btrfs/snapshots/2019-02-02_14-14-37
feb 02 14:17:43 emanuc timeshift-gtk.desktop[11186]: Cartella creata: /mnt/timeshift/backup/timeshift-btrfs/snapshots/2019-02-02_14-17-43
feb 03 19:00:37 emanuc timeshift-gtk.desktop[2935]: Cartella eliminata: /mnt/timeshift/backup/timeshift-btrfs/snapshots/2019-02-02_14-17-43
feb 04 13:26:35 emanuc snapd[1363]: udevmon.go:190: udev monitor observed remove event for unknown device "/sys/kernel/slab/btrfs_inode/cgroup/btrfs_inode(359:systemd-fsckd.service)"
feb 04 14:23:40 emanuc snapd[1363]: udevmon.go:190: udev monitor observed remove event for unknown device "/sys/kernel/slab/btrfs_inode/cgroup/btrfs_inode(933:rtkit-daemon.service)"
feb 04 14:23:41 emanuc snapd[1363]: udevmon.go:190: udev monitor observed remove event for unknown device "/sys/kernel/slab/btrfs_inode/cgroup/btrfs_inode(693:acpid.service)"
feb 04 19:24:35 emanuc snapd[1249]: udevmon.go:190: udev monitor observed remove event for unknown device "/sys/kernel/slab/btrfs_inode/cgroup/btrfs_inode(359:systemd-fsckd.service)"
feb 04 19:48:52 emanuc 05efi[28839]: debug: /dev/sdb1 is btrfs partition: exiting
feb 04 21:27:41 emanuc snapd[1230]: udevmon.go:190: udev monitor observed remove event for unknown device "/sys/kernel/slab/btrfs_inode/cgroup/btrfs_inode(351:systemd-fsckd.service)"
feb 04 22:44:42 emanuc snapd[1230]: udevmon.go:190: udev monitor observed remove event for unknown device "/sys/kernel/slab/btrfs_inode/cgroup/btrfs_inode(661:acpid.service)"
feb 05 09:49:34 emanuc snapd[1238]: udevmon.go:190: udev monitor observed remove event for unknown device "/sys/kernel/slab/btrfs_inode/cgroup/btrfs_inode(345:systemd-fsckd.service)"
feb 05 10:51:42 emanuc 05efi[24521]: debug: /dev/sdb1 is btrfs partition: exiting